Comparative assessment of PIV-based pressure evaluation techniques Part 2: application of techniques

Abstract

In the PIV-based pressure determination approach, PIV-data is used to provide the material acceleration, which is then used to calculate the pressure gradient via the momentum equation, and the pressure is subsequently obtained by spatial integration. Over the years, different techniques have been proposed that follow this approach (see van Oudheusden 2013 for a recent overview). Although several studies have also addressed the comparative performance of different techniques, the number of methods compared in a single study is commonly limited. Also, as different test flow cases are usually considered, no clear consistency among different studies exists. Therefore, there is a clear lack of a consistent and systematic comparative study, in which multiple different methods are applied on the same test case for pressure determination. It is the objective of the present study to better reveal and understand the strengths and weaknesses of various techniques, through assessing the application of a large number of current state-of-the-art PIV-based pressure determination techniques to a single test case, comprising the transonic flow over an axisymmetric step. The present paper focuses on the application of the different techniques and the results of the assessment, while the test case is discussed in detail in a companion paper, which also contains a more elaborate introduction to the work. The pressure evaluation techniques that are considered in the present study are listed in Table 1, and are discussed in more detail in Chapter 2.